package chapter05.e4;

public class e4 {
    public static void main(String[] args) {
        String s = "stcast";
        System.out.println(s.replace("it", "cn,it"));
        String s1 = "  i t c a s t  ";
        System.out.println(s1.trim());
        System.out.println(s1.replace(" ", ""));
    }
}

